(1) Field of the Invention
The present invention relates to a plasma display panel (PDP) used such as for a display device, and to a PDP production method.
(2) Description of the Prior Art
A plasma display panel (PDP) has recently received much attention as a flat panel display used in computers and televisions.
A PDP is classified as one of two major types, namely a DC-type and an AC-type, of which the latter has become mainstream because it is suitable for use in a large display.
To illuminate discharge cells of an AC-type PDP, an AC pulse voltage is applied to electrodes covered by a dielectric layer that sustains a discharge. With an AC-type PDP, a surface-discharge type and an opposed-discharge type are widely known. For the surface-discharge type, pairs of sustained electrodes are placed in parallel on a front panel. For the opposed-discharge type, pairs of sustained electrodes are placed on both the front panel and the back panel, and so the pairs of sustained electrodes face one another.
FIG. 10 shows a standard AC surface-discharge PDP as one example.
For this PDP, a front panel 110 and a back panel 120 face each other, and outer parts (not shown in the figure) of their facing surfaces are bonded with a sealing material made of low-melting glass.
For the front panel 110, pairs 112a–112b of display electrodes are formed on a front substrate 111 on a side facing the back panel 120. A dielectric layer 113 made of dielectric glass, and a protecting layer 114 made of magnesium oxide (MgO) cover the display electrode pairs 112a and 112b. 
For the back panel 120, address electrodes 122 are formed in parallel at certain intervals on a back substrate 121 on a side facing the front panel 110. A back dielectric layer 123 covers the address electrodes 122, and partitions 130 are formed in parallel at certain intervals on the back dielectric layer 123 along the address electrodes 122. Phosphor layers 140 for respective colors (red, green, and blue) are formed in channels between the partitions 130.
With the above construction, the display electrode pairs 112a and 112b are placed perpendicular to the address electrodes 122. At intersections of the display electrode pairs 112a–112b and the address electrodes 122, discharge cells are formed.
Based on image data to be displayed, an address pulse voltage is first placed between the address electrodes 122 and the display electrode pair 112a. After this, a sustain pulse voltage is placed between the display electrode pair 112a and 112b. This causes a sustained discharge to occur selectively in the discharge cells, so that ultraviolet rays are emitted from the discharge cells where the sustained discharge occurs. The emitted ultraviolet rays excite the RGB phosphor layers 140, which then emit visible light, so that images are displayed on the PDP.
Adjacent discharge cells are separated by the partitions 130, which prevent a crosstalk phenomenon, i.e., a state in which discharges at different discharge cells mix, from occurring.
The partitions 130 are usually produced by having a partition material such as a glass material formed into a partition pattern (i.e., stripes) and baking the formed partition material at a temperature higher than a softening point of the glass material contained in the partition material. There are three major partition forming methods as follows. The first one is called a “printing method”, with which a partition pattern is printed using a paste containing the partition material, such as by the screen printing. The second method is called a “sandblasting method”. For this method, the above paste is applied onto the entire surface of the back substrate, and then a photosensitive film layer is formed on this paste. The predetermined partition pattern is then formed using photography. After this, unnecessary paste is removed by sandblasting. The third method is called a “photo-paste method”. In this method, a photosensitive paste containing the partition material is applied onto the entire surface of the back substrate, and then unnecessary portions are removed using photography.
When a partition material is formed into a partition pattern using any of the above three partition forming methods and then baked, an end part 130a of a resulting partition 130 swells and becomes higher than other parts, such as a part 130a. When compared with the part 130b, this end part 130a becomes high by ten to twenty percent.
A swelling such as in the end part 130a is likely to be generated especially when the partitions 130 are formed on the back dielectric layer 123 on the back substrate 121.
The swellings in the end parts of the partitions 130, however, make it difficult to join a back substrate and a front substrate together without leaving any gaps between the partitions 130 and the front substrate during an assembly of a PDP. When this PDP with gaps is driven, an improper discharge or an abnormal discharge is likely to occur in adjacent cells. In addition, due to the above gaps, the front panel vibrates, so that noise is likely to be generated.